Research Roundup

Preference for Beauty Might Be Hard-wired

Experiments conducted by Dr. Ingrid Olson, a research associate in the psychology department and researcher at Penn’s Center for Cognitive Neuroscience, in which subjects were given a fraction of a second to judge “attractiveness,” offered further evidence that our preference for beauty might be hard-wired. People who participated in the studies were also more likely to associate pretty faces with positive traits.

Dr. Olson, along with co-author Dr. Christy Marshuetz, of Yale University, recently published their findings in the journal Emotion, a publication of the American Psychological Association. The researchers set out to study cognitive processes behind a very real phenomenon: physically attractive people have advantages that unattractive people do not. Attractive people are paid more, are judged to be more intelligent and will receive more attention in most facets of life. “This favoritism, while poorly understood, seems to be innate and cross-cultural. Studies suggest that even infants prefer pretty faces,” Dr. Olson said.

In their report, the researchers describe three experiments to investigate the preference for attractiveness. The first study tested the idea that beauty can be assessed rapidly by asking study participants to rate faces—pictures of non-famous males and females taken from three different high school yearbooks and the Internet—shown for .013 seconds on a computer screen. Although participants reported that they could not see the faces and that they were guessing on each trial, they were able to accurately rate the attractiveness of those faces.

In their second and third experiments, the researchers explored the notion of “priming”—whether or not seeing a pretty face makes a viewer more likely to associate that face with positive attributes. The second experiment involved rapidly showing a face on the screen, followed shortly thereafter by a word in white text on a black screen. Participants were instructed to ignore the face and were timed on how quickly they could classify the word as either good or bad. Almost uniformly, response times to good words, such as “laughter” or “happiness,” were faster after viewing an attractive face.

They repeated the priming test in a third experiment, this time using images of houses, to see whether the beauty bias is a general phenomenon or one that is limited to socially important stimuli such as faces. Unlike faces, response times to good words were not faster after having viewed an attractive house.

Baboons in Mourning Seek Comfort Among Friends

When Sylvia the baboon lost Sierra, her closest grooming partner and daughter, to a lion, she responded in a way that would be considered very human-like: she looked to friends for support. According to Penn researchers, baboons physiologically respond to bereavement in ways similar to humans, with an increase in stress hormones called glucocorticoids. Baboons can lower their glucocorticoid levels through friendly social contact, expanding their social network after the loss of specific close companions.

“At the time of Sierra’s death, we considered Sylvia to be the queen of mean. She is a very high-ranking, 23 year-old monkey who was, at best, disdainful of females other than Sierra,” said Dr. Anne Engh, a postdoctoral researcher in the biology department. “With Sierra gone, Sylvia experienced what could only really be described as depression, corresponding with an increase in her glucocorticoid levels.”

Dr. Engh worked with Dr. Dorothy Cheney, professor of biology and Dr. Robert Seyfarth, professor of psychology. For the last 14 years, Drs. Cheney and Seyfarth have followed a troop of more than 80 free-ranging baboons in the Okavango Delta of Botswana. Their research explores the mechanisms that might be the basis of primate social relationships and how such relationships may have influenced the development of human social relationships, intelligence and language.

To study the response of stress among baboons, Dr. Engh and her colleagues examined the glucocorticoid levels and grooming behavior of the females in the troop to see how closely they resemble patterns seen in humans. Their findings were published in the Proceedings of the Royal Society of Biological Sciences.

According to Dr. Engh, while the death of a close family member was stressful over the short term, the females they studied appeared to compensate for this loss by broadening and strengthening their grooming networks, which resulted in their glucocorticoid levels returning to normal.

Dr. Engh was able to track patterns in stress of the female baboons over time through their glucocorticoid levels. The stress levels of female baboons increased most noticeably when a predator killed a close companion. If they merely witness another baboon die they do not become as agitated.

“Our findings do not necessarily suggest that baboons experience grief like humans do, but they do offer evidence of the importance of social bonds amongst baboons,” Dr. Engh said. “Like humans, baboons seem to rely on friendly relationships to help them cope with stressful situations.”

Night Eating Syndrome & Psychiatric Outpatients

According to a study that appeared in the January 1 issue of The American Journal of Psychiatry, researchers at Penn’sSchool of Medicineand the University of Minnesota found that night eating syndrome is a common disorder among psychiatric outpatients and is associated with substance use and obesity.

“This is the first study that looks at the connection between psychiatric conditions and night eating syndrome,” said Dr. Jennifer D. Lundgren, lead author of the paper and postdoctoral research associate in the psychiatry department, Division of Weight and Eating Disorders. “Night eating syndrome is often associated with life stress and depression, so we were particularly interested in looking at the prevalence of the condition in this population,” said Dr. Lundgren.

The study consisted of 399 participants from psychiatric outpatient clinics. Participants were screened using a questionnaire to assess hunger and craving patterns, percentage of calories consumed following the evening meal, insomnia and awakenings, nocturnal food cravings and ingestions, and mood. Those who scored above cutoff on the questionnaire were then interviewed by phone and diagnosed with night eating syndrome if one or both of the following criteria were met: 1) evening hyperphagia and/or 2) nocturnal awakenings with ingestions of food occurring three or more times per week.

Based on the total group of 399 participants, the prevalence of night eating syndrome was 12.3%, which exceeds the prevalence of the condition in an obesity clinic. The study revealed a significant effect of night eating syndrome diagnosis on body mass index (subjects with night eating syndrome: mean=33.1kg/m2; subjects without night eating syndrome: mean=27.7 kg/m2). Additionally, obesity was present in 57.1% of participants with night eating syndrome and obese patients with psychiatric conditions were five times more likely than non-obese patients to exhibit the condition.

Substance abuse was also more likely to occur among patients with night eating syndrome (30.6%) than among those without night eating syndrome (8.3%). Alcohol was the most commonly abused substance.

“Given the prevalence of night eating syndrome among outpatients with psychiatric conditions, our findings indicate that mental health practitioners will need to screen for and incorporate appropriate treatment options into their practice,” said Dr. John P. O’Reardon, a co-author of the study, assistant professor of psychiatry, and director of Penn’s Treatment Resistant Depression Clinic.

fMRI Used to Detect Memory Storage and Retrieval

Using functional magnetic resonance imaging, or fMRI, researchers at Penn and Princeton University have provided evidence that the act of recalling a memory is a bit like mental time travel. Their study, presented in the December 23 edition of the journal Science, demonstrates that the same areas of the brain that are active during an event are activated when a person attempts to recall that event seconds before the memory surfaces.

“An everyday strategy for getting at lost memories involves using a part of a memory to pull out the entire thought, much like when you try to remember where you put your keys last night,” said Dr. Sean Polyn, a postdoctoral fellow at the Computational Memory Lab in Penn’s department of psychology. “If you recall that you were washing dishes, that might trigger associated memories, leading you to remember that your keys are next to the sink. We refer to this phenomenon as ‘bootstrapping.’”

Dr. Polyn believes that the knowledge of how the brain uses its memories could be applied to designing more detailed models of memory, which could help treat brain disorders such as Alzheimer’s disease and epilepsy.

Dr. Polyn and his Princeton colleagues gave participants 90 things to remember divided among celebrity faces, common objects and famous locations using the fMRI to detect which parts of the brain were involved in the learning process for each category. They developed a technique that could track the brain activity corresponding to each of these categories. As they remembered, the technique provided a second-by-second readout of how the brain searched for information.

So participants would not feel compelled to “cram” the 90 items, the researchers presented them in the form of a series of judgments, for example, asking whether or not the subject liked or disliked a labeled photograph of comedian Carrot Top. These judgments were interspersed with simple arithmetic questions to keep the participants from memorizing the items. The subjects were then asked to freely recall the 90 items, in whatever order they could.

As the research team reviewed the data, they could see how the portions of the brain that stored memories of faces, for example, would activate several seconds before the participant began to name the celebrities.

“The results of this experiment suggest that when we think back to the past, each detail we remember triggers another, until the memory returns completely,” Dr. Polyn said.